Turbine.



s. 2. DE PERRANTL' Patented Oct. 1908-.

5 SHEETS-$113121 1.

. N 7 P I. s 1. o H m o /.A 8 VVV o 5 -V// 1 v S. Z. DE-PERRAN'IL TURBINE.- APPLICATION FILED SEPT. 16, 1907.

901 1931 Patented Oct. 20,1908.

5 SHEETS-SHEET 2.

- Ew76g07i S. Z. DE FERRANTI.

TURBINE. APPLICATION FILEJSEPT. 16, 1907.

Patented 0ct. '20,1908.

5 SHEBTS-SEBET 3.

S. Z. DE FERRANTI.

TURBINE.

APPLICATION FILED SEPT. 16, 1907.

Patented Oct. 20, 1908.

- 5 SHEETS-SHEETML S. Z. DE PERRANTI.

TURBINE. APPLICATION FILED SEPT.16, 1907.

901,931. Patented Oct. 20,1908.

5 SHEETS-SHEET 5.

wawwa M g%-%@ 1% M UNITED STATES PATENT cr me-EL SEBASTIAN ZIANI DE FERRANTI, OF GRINDLEFORD, NEAR SHEFFIELD, ENGLAND. I 1

TUBB INE Specification of Letters Patent.

Patented Oct. 20,1908.

Original application filed. October 31, 1903, Serial No.179,407.. Divided and this application filed September 16, 1907.

. Serial No. 393,125. i

To all whom it may concern:

Be it known that I, SEBASTIAN ZIANI on FERRANTI, a subject of the King of Great.

Britain and Ireland, and residing at Grindleford, near Sheflield, in the county of Derby,

England, have invented certain new and use- In turbines of the type in question, the

working fluid is expanded in a number of.

stages with'intermediate re-heating so that the. expansion on the whole may be substantially isothermal; j

The present 1nvention consists in superheating the fluidprior'to its isothermal expansion in the turbine so that'on the one hand a higher thermal efficiency may be obtained and on the other hand a higher mechanical efiicienjcyfowing to the use of dry fluid only in the turbine and a conse uent large reduction in the fluid friction. lhese advantages will be more clearly understood by comparison with Figure 16 of the accompanying drawings. This Fig. No. 16 shows an entropy 4 temperature diagram of the cycle through which the fluid passes when no initial superheatinglis provided. In this figure, the steam (ta 'ng steam by way of example of a suitable working fluid) when de" livered to the turbine will be to a certain extent-wet as in ordinary practice, its state be ing represented by the point E.

After adiabatic expansion in the first stag? of the turbine, the steam isin the state first re-heater first dries the Working fluid, its

line F G, and subsequently super-heats to say the boiler temperature. Further adiabatic expansions G H and re-heats H G then take place as shown in the diagram. The disadvantages of'suoh a cycle are that the heat taken in alon the line F G in particular is imparted to the lluid at a comparatively low temperature and .is consequently in accordance with well'khown principles inefficiently converted into worlr while even in subsequent reheats,the temperature throughout is below the highest. lnlence the thermal efliciency of and is still. necessarily wet. The heat received in the employed. i) a compound or multiple stage impact I the cycle due to the reheating is probably not substantially altered. The mechanical efliciency is, however, improved since, after the first ex ansion, the steam is dry and hence the fluid friction due to wet. steam is absent. All these disa'dvanta es are overcome, however, by initial super eating of the steam as shown in the illustrative examples given in Figs. 12 to 15. In such cycles it will be seen that the steam is dry throughout its whole expansion in'the turbine, fluid friction being thereby reduced to a minimum, while the heat taken in by the fluid from the re-heaters is taken in at ahigh temperature and is therefore very efficiently converted. To sum up, therefore, both the mechanical and thermal efficiencies of the turbine areincreased by initial 'superheating of the steam.

Referring to the accompanying drawings,

Fig. 1 shows the general arrangement in elea vation of a complete installationof lant having fire-heated superheaters and reeat ers, Figs. 2, 3 and 4 being corresponding sections onthe lines X X, Y Yand Z Z respectively of Fig. 1. i Fig. 5 shows a nlodification of the arrangement of Fig; ,1, and- Fig. 6 an arrangement adapted tothe case of a Lancashire or other" flue boiler. Fig. 7

shows another general arrangement in which superheated steam is employed in the re heaters; Fig. 8 is a detail view showing analternative arrangement of thereheater coils Fig. 9- is a modification of the arrangement of the re-heaters of Fig. 7, while Figs. 10V and I 11 show diagrammatically othermethods of reheating by means olisuperheated steam;

Figs. 12 to 15 are sketches of entropy-tern perature diagrams showing examples of 3 8;?

rious operative cycles according to the pres ,ent invention, Fig. 16 being an explanatory diagram.

I 'll describe my invention as applied to one modification in what I consider its best form, via, with all the elements combined together in one machine so as to obtain the highest economy. l will assuine the turbine is to use steam as the medium of expansion and that it is desired to employ a compound turbine of the impact type, although it will be seen that any condensable elastic fluid,

may be used and that acompound turbine of any of the other well known types may be l therefore construct (Figs. 1 to exhaust is in steam turbine a in a well known manner but I separate each stage in such a way that I can pass the steam exhausting from the first stage through a reheater delivering into the inlet of the second stage and from its exhaust to a second reheater and so on, re-heating after each stage expansion to the final exhaust. I arrange the turbine a, on a horizontal shaft and provide the reheaters below the turbine body. These re-heaters, d c are tube elements situated in a combustion flue, d, which also contains the boiler, e f, superheater, h i, and water heater is, Z, elements.

In connection with the exhaust passage, m, of the turbine, I arrange a coil regenerator, n, so as to extract the heat from the exhaust iwhichcomesfrom the turbine at atemperature ap roaching the maximum temperature of t e cycle; I arrange the water supply to the inlet of this regenerator to come from the condenser u or from the hot well by way of the pipe 0, and I connect the regenerator outlet p which is nearest to the turbine, pref: erably to the water heater element, by way of the pipe 1' so that the heat of the turbine fl part restored to the working uid.

I find it convenient to employ boiler, e f

and superheater elements it '11 of a similar character, which may take the form of up er and lower drums, joined by a large num er of nearly'vertical tubes, which traverse the flue d, and therefore bafiiethe combustion gases. Theboiler, 'superheater, reheater and water heater elements are all arranged in the flue, d, in such a way as to obtain the best extraction of heat from the gases of combustion, which are produced and burned from one end of the furnace. I may also employ coaldust as the furnace combustible.

- Beneath oraround the furnace flue, carrying the boiler, superheater, reheater and water heater elements, I'prefer to construct fines to carry the roducts of'combustion to the chimney s an through these waste gas fiues I carry iron air ducts t, whichfconv'ey the air supply to the furnace in a direction prefereably counter to the fiow of thewaste gases, thus forming an air regenerator and obtaining hot air for the fuel combustion.

According to a modification as shown in Fig. 5 the length of piping between the tur-- bine and re-heaters is reduced to a minimum, the regenerator being removed from the position shown in Fig. 1 and placed beyond the flue heated elements. other form of reheater consisting in one or more heaters from which tubes depend. Fig.' 6 shows an arrangement of arts in which a Lancashire or other flue oiler is used instead .of the water tubeboilers of Fig.

1. The same letters are used in the last two figures as in Fig. 1 to denote similar parts.

r According to another modification shown Figs. 7, 8 and-.9 instead of direct fire heatheater through the Fig. 5 also -shows.an-

ing of the reheaters, I arrange them to be heated indirectly by superheated steam.

' Thus in Fig. 7, the steam generator is shown 'at 2,'provided with steam drums 3, from a the pipe 8, passing through them in arallel.

A pump 9, is provided to return t e condensed steam issuing through the pipe 25, from the reheaters to the boiler through the ipe, 10, feed water-heater 26 and pipe 27.

. he arrangement I prefer in the reheaters is to conduct the steam from the turbine after the first stage of expansion through the pipe 11, to the bottom of the first re-heater and then upwards in a direction counter to that of the superheated steam through the coil 12, and back to the turbine. This action is repeated after each stage of expansion in the turbine, the steam finally passing through the exhaust pi e, 13, to the regenerator, 14'. Itwill be un erstood that as the figure is merely diagrammatic, the proportions, of ,reheater coils, and the other parts are not those which would be adopted In practice.

An alternative arrangement of the reheater coils is shown in Fig. 8, steam from the turbine being led to-the bottom of the reheater through the pipe 15, whence it returns through the. pipe 16, meanwhile traveling in mop o site direction to that of the superheate steam which enters the top of the reipe 17, and flows through the coil 18, to its outlet after which its ath back to the boiler is as before.

eferring again to Fig. 7, the steam from the turbine passes through the regenerator to the condenser 19, which may be of the jet condensing type, supplied with cooling water through the pipe 20, and provided with an air pump 21. Another pum 22, which may if convenient, be worked 0 the air pump, 21., serves to pass a partof the outflow from the condenser through the regenerator coils, 28, whence it passes on and joins the condensed steam from the reheaters. The combined steam may then be pum ed through the economizer or feed water eater, 26,-placed .in the uptake and returned to the boiler, thus completing the cycle.

In Fig. 8, is shown another arrangement of the re-he'aters; the coils 12, through which the steam fromthe turbine passes, are in this case arranged in one large compartment, 24, superheated steam entering through the pipe, 8, as before and leaving after condensa tion, by the pipe, 25, after which its course is as described above.

Instead of dividing the St permeated steam eoheei 7 into two parts according to the methods of Figs. 7 and 9 I may use the following system. Steam from the generator 2, (see Fig. 10) is led through the pipe, 29 to the superheater 30; after being superheated in the' coils 31, it passes through the pipe 32, direct to .the re-heaters 33, which are 1n this case,

preferably of the type shown in Fig. 8. The

' through the re-heaters. Steam from the gen erator 2, passes as before, through the pipe 29, to the coils 31, of the superheater 30, it then passes through the ipe 38, to the reheaters 39. These are of the same general type as those shown in Fig. 8, exce tthat the coils are divided into upper and ower sets.

The steam after passing through the upper coils, 40, 40, of the re-heaters returns through the pipe 41, to the coils 35, 36, ofthe superheater and after issuing thence divides nto "two parts, the one part passing through the stage'expansion impact type.

pipe, 42, to the turbine and the other part by way of the pipe 43, through the lower coils 44, 44, of the reheaters, thewater of condensation being returned by the pump, 45, to the generator, either dlrectl through the pipe, 46, or indirectly'through a feed water eater such as is shown-at 26, Fig. '7.-

With regard tothe turbine itself, as above mentioned, it is of the compound or multiple Each stage of theexpansion thus -forms a turbine of he jet chamber of the second stage is sup- 1) what is known as the Laval type. Each air of fixed and movingelc ments of this tur ine also constitutes a complete turbine in which the drop of pressure is arranged to take lace in the jets of the fixed element only.

plied through the first re-heater, and here again the drop of pressure takes place in the fixed jets ofthe second stage, and so on through the various stages of expansion in the turbine down to the exhaust.

It will be seen that by means of thereheaters provided at each stage of expansion,

the temperature of the turbine is maintained.

practically uniform from end to end, and the exhaust steam will pass from the turbine practically at the temperature at which it at each stage passes to-the reheater, the larger the number of stages employed the nearer being the approach to isothermal expansion.

ejector condenser employing practically air- The exhaust steam thendelivers through a passage, in which is situated the .regenerator for the extraction of its heat, and then into the condenser, which is preferably a jet or freed water.

It will be seen that various elements of my complete isothermal expansion power generator may be omitted without departing from my invention, although oicourse, the omission of these elements will involve a less economical productionof power. For exainple:- v (a) Theregenerator maybe omitted and in this case the isothermal expansion is only carried over a portion of the range theremainder of the expansion being efiec'ted adiabatically; reheating should, however, be carried to such a stage as to insure a slightly superheat exhaust. I find it possible to se cure a considerable gain in economy by the use of only three reheating stages, the steam from the last of these being preferably expanded adiabaticallyand passed through the regenerator. I (b) It will be obvious that the air regen' erator may be omitted and also the'condenser although such onlissioiis will involve a smaller advantage.

It willbe seen that an isothermal expansion turbine of my new type has to work under the maximum temperature of thecycle. This has the disadvantage that lubrication is rendered more difficult.- It has, however, several great advantages. One of these is that the steam can be maintained practically dry throughout the whole ran e of expansion. This fact has great in uence in re ducing the frictional losses in the turbine.

erent parts of the turbine practically diseilrtpansion du'e'to unequal heating of the I ppear. 4

Although I have used the term isothermal expansion in setting forth'my invention I am, nevertheless aware that the exansion through each stage is actually closely adiabatic. The effect of the reeheaters taken in conjunction with the adiabatic expansion, is however, to causethe resultant expansion line to cross and re-cross an isothermal line drawn at about the mean temperature of the re-heats, said expansion line thus approximating to such an isothermal line more or less closely according to, the number of reheats and it is in thissense that I wish the words isothermal ex ansion to be con strued, both in the b0 y of the and inthe followingclaims.

It will be seenthat many modifications can be made in the details of the cyclesemployed without departing from the essence of my'invention and in order to explain more fully the sense in which I use the term iso:

specification 'Again no great variations of temperature The difficulties ordinarily oc- &

stitutin the Figs. 12 to 15 are practically self-exp anatory, the expansions in the differnt tur ine stages being in each case represented by the substantially adiabatic lines,

"A B, while the intermediate re-heats are shown by the lines, B A. The figures at the various points of the diagram are by way of example of the temperatures existing at these points in degrees centigrade. It will be seen that in each example given the resultant expansion line continually crosses and re-c'rosses the dotted isothermal line, C D, which is drawn at about the mean temperature of the re-heats. i

Having now described my invention, what' I claim as new and desire to secure by Letters Patent is 4 1. In combination with a plurality of elastic fluid motors wherein said fluid undergoes progressive expansions, means for initially superheating said fluid together with means for maintaining the temperature of said fluid at the inlets of the second and following motors equalto the temperature of superheat atthe inlet of the first of said motors.

2. In combination with a plurality of elastic fluid motors wherein said fluid undergoes progressive expansions, means for initially superheating said fluid together with means for maintaining the temperature of said fluid at the inlets of the second and following. motors equal to the temperature ofsuper heat at the inlet of the first of said motors, together with a regenerator through which the exhaust fluid is passed.

3. In combination with a plurality of elastic fluid motors, wherein said fluid undergoes progressive expansions, means for initially superheating the fluid together with means disposed between successive expansions for re-heating said fluid, the mean temperatures of the re-heats being substantially identical.

4. In combination with a )lurality of elastic fluid motors wherein sai fluid undergoes progressive expansion, means for superheating the fluid at some point of the total expansion, together with means disposed be tween successive expansions after said superheati'ng point for re-heating said fluid at each re-heat to the superheating temperature.

5. In combination with a plurality of elastic fluid motors, wherein said fluid undergoes progressive expansions, means for superheating the fluid at some point of the total ex pansion together with means disposed between successive expansions after said superheating point for heating said fluid to a uniform high temperature.

6. Incombination with a lurality of elastic fluid motors, wherein said fluid undergoes together wit progressive expansions, means for supe'rheat .65;;

re-heat to such'an extent that the next ex pansion is not suflicient to bring said fluid to the saturated condition, the mean tempera- .tures of the re-heats being substantially identical.

7. In combination with agtlurality of elastic fluid motors, wherein sai uid undergoes progressive expansions, means for nitially superheating said fluids g eans for expanding I said superheated fluid adiabatically in said motorsand means disposed between said adiabatic expansions for re heating said fluid to thetemperature of'superheat at each reheat. 8. In combination with a plurality of elastic fluid motors, wherein saidi fluid undergoes progressive expansions means for initially superheatingsigd flu1d; .means for ex-anding said superheatedjfluid 'adiabatic'a yin said motors and means disposed between said adiabatic expansions for'r'e-heating said fluid so as to render the ex ansion-on the whole substantially isotherms. 9. In combination witha lurality of elastic fluid motors, wherein said fluid undergoes progressive expansions, means for initially.

superheating said fluid; means disposed be tween said expansions for reheating the fluld so as torender the expansiorionthe whole 5 V substantially isothermal together vsuth" ;a'fji regenerator through which the exhaust fluidfi'o'o passes.

10. In combination with a plurality of elastic fluid motors, wherein said fluid undergoes progressiveexpansions, means for superheating the fluid at some point of the total expansion; means disposed between successive expansions after said superheating point for heating said fluid at each re-heat to such an extent that the next expansion is not sufficient to bring said fluid to the saturated condition, the mean temperaturesof the reheats being substantially identical, together with a regenerator through which the exhaust fluid passes.

'11. In combination, a plurality of turbine I chambers; sup erheating means connected to the inlet of one of said chambers; combustion means for generating 'hot gases; re-" heaters operatively connected between certain of said chambers, said reheaters being disposed in the path of said hot gases to abstract a proportion of the heat of the same means for abstracting a further. proportion of said heat.

12-. In combination a lurality of turbine chambers,- flue means or conducting hot gases; superheater, reheater,' elastic fluid regenerator and feed water heater elements, 

